PURPOSE: Fermented grape pomace containing humus obtained by fermentation of the seed, skin and stem of grape which have hitherto been discarded is provided, which effectively increases the livestock weight, improves the productivity and shows little side effects to livestock. CONSTITUTION: Grape pomace such as drained seed, skin and stem of grape is fermented, ground and dried. The fermented grape pomace is added to feed in an amount of 2 to 6% by weight as a feed additive, based on the total weight of the feed. The feed additive is effective for poultry for increasing the egg weight in the early period of egg-laying and livestock in the growth period.
